This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Gorgon, a software collaboration between Matthew Baker at BCM and Tao Ju at Washington University in St. Louis, is an interactive molecular modeling toolkit specifically targeted at subnanometer to near-atomic resolution density maps from cryo-EM. Gorgon provides a comprehensive visualization framework for volumetric data, geometric skeletons, secondary structure elements and atomic models. Additionally, gorgon provides tools for identifying the correspondence between predicted secondary structure elements in the sequence and the observed secondary structure elements in the volume. From this correspondence,users can semi-automatically or interactively construct a C-alpha backbone model with the tools provided within Gorgon. The long-term goal of the Gorgon project is to produce an integrated environment for the complete analysis, annotation and modeling of complex macromolecular structures.